In general, a biomaterial may be divided into hard tissue and soft tissue. Bones or teeth are examples of the hard tissue. Skin, blood vessels, cartilages, or ligaments are examples of the soft tissue. The hard tissue has an elastic coefficient and a tensile strength that are higher than those of the soft tissue.
The soft tissue as a biomaterial has been used in the field of dental treatment. In particular, soft tissue transplantation surgeries have been widely used as a method for rebuilding or treating damaged soft tissues during a dental surgery such as implant surgery.
In case of an implant surgery that is recently in the limelight, gums around an implant need to be healthy so that a tooth implant may be used for a long time. This is the same principle that is used for a case in which a flag driven into sands. The flag does not fall when a large amount of sand exists around the flag. That is, even when an alveolar bone firmly holds the root of a tooth, the tooth may sway when the gum surrounding the tooth is insufficient. Also, exposed nerves may cause pain and it is not aesthetic. In this case, a soft tissue transplantation surgery is needed.
To transplant soft tissues to an area where the thickness of a gum is thin or the gum is lost, soft tissue to be transplanted needs to be primarily obtained. To this end, soft tissues in an amount needed for transplantation are cut off from other normal area in the oral cavity. Typically, soft tissues in the palate of the oral cavity are used because the flesh of the palate is relatively thicker than that of other places.
Dental instruments for cutting soft tissue are used to cut the soft tissue off from the oral cavity to provide soft tissue used for a soft tissue transplantation surgery.
A conventional dental instrument for cutting soft tissue may include a main body equipped with a blade, a cover covering the upper portion of the main body, and a handle coupled to the main body and held by an operator. The blade is coupled to the main body by being separated therefrom to have a predetermined cutting depth. Also, the main body and the cover may be formed in a single body.
In the meantime, soft tissue cut including the outer surface of a particular portion in the oral cavity may be used as the soft tissue to be transplanted in a portion having a thin thickness or in a place where gum is lost. However, it is advantageous to use soft tissue arranged at a predetermined depth under the outer surface of the particular portion in the oral cavity because of a high transplantation success rate.
Since the conventional dental instrument for cutting soft tissue is equipped with a single blade having a predetermined cutting depth, to cut soft tissue arranged at a predetermined depth under the outer surface of the particular portion in the oral cavity, soft tissue is primarily cut by a predetermined depth under the outer surface and secondarily soft tissue by a desired thickness is cut off from the portion where the outer surface is removed.
In addition, the cutting depth of a blade installed at a dental instrument for cutting soft tissue used for the first cutting process is different from that of a blade installed at a dental instrument for cutting soft tissue used for the second cutting process. Thus, two or more dental instruments for cutting soft tissue are needed for cutting soft tissue. Furthermore, when a single dental instrument for cutting soft tissue is in use, it is inconvenient to replace the blade for each process.